Disconnection of vehicle electric system using low voltage switch

Abstract

A power system ( 100, 200 ) for a vehicle, the power system comprising: a hazardous voltage interlock loop (HVIL) circuit ( 106 ) configured to disconnect a high-voltage energy source ( 102 ) from a high-voltage system ( 104 ); a low-voltage energy source ( 108 ) coupled to the HVIL-circuit for supplying operational power to the HVIL-circuit; and a circuit breaker ( 110 ) operable to break a connection between the low-voltage energy source and the HVIL circuit, wherein the HVIL-circuit is configured to disconnect the high-voltage energy source from the high-voltage system if the low-voltage energy source is disconnected from the HVIL-circuit.

The invention claimed is: 
     
       1. A power system for a vehicle, the power system comprising: a hazardous voltage interlock loop (HVIL) circuit configured to disconnect a high-voltage energy source from a high-voltage system; a low-voltage energy source coupled to the HVIL-circuit for supplying operational power to the HVIL-circuit; and a circuit breaker arranged to be accessible from an outside of the vehicle and manually operable to break a connection between the low-voltage energy source and the HVIL-circuit, wherein the HVIL-circuit is configured to disconnect the high-voltage energy source from the high-voltage system if the low-voltage energy source is disconnected from the HVIL-circuit. 
     
     
       2. The power system according to  claim 1 , wherein the circuit breaker is configured to physically break the connection between the low-voltage energy source and the HVIL circuit. 
     
     
       3. The power system according to  claim 1 , wherein the circuit breaker further comprises a visual identifier configured to enhance the visibility of the circuit breaker in relation to the vehicle. 
     
     
       4. The power system according to  claim 1 , comprising two circuit breakers arranged at opposing sides of the vehicle, wherein each circuit breaker is configured to break a connection between the low-voltage energy source and the HVIL circuit. 
     
     
       5. The power system according to  claim 1 , wherein the HVIL-circuit comprises a first contactor arranged to disconnect a positive pole of the high-voltage energy source from the high-voltage system. 
     
     
       6. The power system according to  claim 5 , wherein the first and/or second contactor is an electromagnetic relay switch. 
     
     
       7. The power system according to  claim 1 , wherein the HVIL-circuit comprises a second contactor arranged to disconnect a negative pole of the high-voltage energy source from the high-voltage system. 
     
     
       8. The power system according to  claim 1 , wherein the HVIL-circuit comprises a current source configured to supply a current to functional components of the HVIL-circuit. 
     
     
       9. The power system according to  claim 1 , wherein the low-voltage energy source is configured to have an operating voltage in the range of 12-48V. 
     
     
       10. The power system according to  claim 1 , wherein the high-voltage system is configured to have an operating voltage higher than 400V. 
     
     
       11. The power system according to  claim 1 , wherein the high-voltage system comprises an electric motor for vehicle propulsion. 
     
     
       12. A vehicle comprising a power system according to  claim 1 .